Road and method of waterproofing the same



March 4 1924. 1,486,015

C. B. FILBERT ROAD AND METHOD OF WATERPROOFING THE SAME Filed Oct. 14, 1922 ATTORNEY Patented er. a, 1924.

ROAD AND EDD 0F WABDOFING THE SAME;

Application filed October 14, 1922. Serial No. 594,588. 7

state, or the'oil may be slightly heated, if

To all whom it may concern:

Be it known that I, CALVERT 'BURKE FIL- BERT, citizen of the United States, residi at New Orleans, in the parish of Orleans aiid State of Louisiana, have invented certain new and useful Improvements in Roads and Methods of W'aterproofing the Same, of which the following is a specification.

In the ordinary methods of oiling or waterproofing macadam, gravel, shell, slag, chert roads and the like, the surface of the roadway is generally swept free of loose material and a single application of bituminous material is applied to the roadway and coated with chips, shells, sand or other suitable mineral aggregate. In many instances, however, the oil or other bituminous material is thin or light in body and is completely absorbed by the road surface. Consequently the oil fails to provide the necessary adherence of the'surface dressing of chips, etc., heretofore mentioned. In other cases, where the oil is sufiiciently heavy to insure the necessary adherence of the surface dressing of chips and the like, there is frequently little or no penetration into the road structure, that is, the road itself does not absorb the oil, and consequently the surface coat of oil and mineral aggregate is subject to pushing and waving from traffic and often completely separates itself from the road structure.

The primary object of the present inven tion is to eliminate the disadvantages in the known methods and to improve the roads treated by my process. In practicing my "invention, the oils or other water-proofing vention, I employ an 01 contaimng mediums are applied to the road surface in two or more successive stages using two different grades or qualities of material, the first of these materials being capable of insuring penetration into the road structure, while the second provides a firm bond or union with the. first and with the carpet coat of mineral aggregate which serves as a wearing surface.

The drawing forming a part of this application shows a cross-section of the road constructed in accordance with the method disclosed, and bearing the legend reciting the steps of the method.

In the first stage or a plication of the inpreferably from 45 to 65 percent asp and of relatively thinfluidity, so that 1t, may if desired be applied to the road surface a cold by weight when teste necessary. The asphalt content, temperature, and extent 0 application of the oil will depend on the texture and density of the old road surface. Oils suitable for the primary or pnming treatments are referably relatively high in volatile constituents,

Prior to the application of these priming 15 to 30 per cent oils, the dry road surface should preferably be brushed free of loosely bonded materia and as many gravel and chert roads do not have suflicient stability to withstand heavy brushing, such roads should only be slightly swept. After the application of the priming oil by mechanical distribution and usually at the rate of from i tog gallon for one square yard, the surface is left undisturbed and preferably free from traffic a sufiicient time to permit the oil to be completely absorbed by the road. In the case of very porous .roads, especially the newly constructed water-bound-macadams and gravel types, it may be advisable to repeat the treatment with the primary oil, but with a less quantity'of the latter. Also any fat spots that may remain on account of inequality of density or compaction of the old road structure should be covered with just suflicient dry sand to absorb the excess bitumen, and

the sand so added removed prior to the application of the secondary oi Volatilization of the lighter constituents of the priming oil after it has been applied to the old road structure results in a our- 6 ing of the road surface due to a hardening or thickening of the oiling material, and the hardening or thickening is progressive in character from the lower layers of the road structure toward the surface or crust.

In the secondary treatment, I preferably use an oil of from 65 to per cent asphalt. content, and which is relatively low in volatility that is,'materials showing less than 15 per cent evaporation loss by the standard .test of the American Society for Testing Materials. These oils are applied to the primed road surface already referred to in a heated condition, and preferably by the use if-mechanical distributors. The temperature of application should preferably be between 275d and 375, de-

" face, this depending l to gallon per square yard of road suron the texture and density of the old-road structure and also on the size of the particles of the material subsequently to be applied as a surface dressing After the secondary oil has been applied, and distributed uniformly by squeegeesii? necessary, the surface dressing of crushed. stone chips,

ravel, slag, shells, or coarse sand or the like is scattered over the oiled surface in the usual manner and then the road is thoroughly rolled. The usual precautions should be taken to insure that the stone chips, gravel or the like are dry and free from dust and fine material.

' remaining unabsorbed is sufiiciently tenacious to hold the stone chips or the like added as the surface dressing or new wearin%surtace.

he present invention provides .a road structure in which the surface coat will remain firmly in position for a long time.

From the foregoing, it is believed that I the steps of the process and the structure of the road formed thereby may be readily understood by those skilled in the art and it is apparent that various changes may be made in the details disclosed without departing from the spirit of the invention as expressed in the claims.

'What is claimed and desired to be secured by Letters Patent is:

1. A method oftreating ready made road structures having a surface portion of porous mineral aggregate, consisting in first removing dust from the surface portion, then applying a priming water-proofing liquid containing asphalt to the remaining. rigid road surface, allowing the major portion of said liquid to be absorbed by the road structure, applying to the road a heavier liquid water-proofing material containing asphalt in a greater proportion than said priming liquid, and-then adding a surface dressing of mineral aggregate substantially coarser than common road dust,

upon the second water-proofing material.

' 2. A method of treating an old road structure'having a surface portion of porous Fahrenheit and the quantity usually mineral aggregate, consisting in first applyin to the surface of a road structure a priming water-proofing liquid medium containing asphalt and capable of penetrating into and binding the elements of the road structure, then ap lying at a temperature at which it is liquld, a second water-procting medium containing asphalt, in a greater proportion than does said priming liquid, and capable of bonding with the first water" proofing medium and providing surface ad herence, and finally applying a surface dressing of mineral aggregate upon the second water-proofing med1um.

3. A method of treating. road structures consisting in first removing dust from the surface of the road structure, then apply ing to the surface of the road structure a relatively thin asphalt-containing oil capa-.

ble of penetrating the road structure and also capable of partial evaporation at atmospheric temperature, then applying a less after the major portion of said oil has been absorbed by the road and a minor portion of the same has been evaporated applying in a li uid condition, a water-proofing medi um of eavier less volatile asphaltic Oll capa ble of bonding to the first mentioned oil and the road surface.

5. In the treatment of old'roads, the here- 7 in described improvement which comprises applying to a porous hard old road surface,

, which is substantially free from top dust,

a priming coat of a thin liquid asphaltic oil, and allowing the major portion thereof to permeate into the hard road body; thereafter applying to such road surface, a viscous asphaltic material in afreely liquid state, such latter material containing a substantially higher percentage of asphalt than the oil used in said riming coat, spreading out said second app ied liquid asphaltic material, then. applying hard granular road metal of a size much coarser than ordinary road dust upon said second applied asphaltic material, and finally rolling said structure.

In testimony whereof I a my signature.

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